Cleaning Soldering Residues from High Lead Soldered PCBs

High lead solder is commonly used for building products that are exposed to environments that exceed temperatures in excess of 200°C. High lead reflow temperatures reach 340-360°C, which can cause flux residues to polymerize and char, making them highly difficult to clean. An additional complication when cleaning high lead circuit assemblies is the softness of lead alloys, which can cause metal oxidization to occur during the cleaning process. The purpose of this research is to discuss high lead cleaning complexity, cleaning fluid designs for addressing chemical attack to the lead solder, cleaning methods and reliability of lead solder joints that change in appearance during the cleaning process.